usage.adoc

Basic usage tutorial

Please note, that svgren uses C++'17 features.

First of all we need to include the svgren header file

#include <svgren/render.hpp>
#include <fsif/native_file.hpp> // we will need this to load the SVG file

Then we need to load the SVG file and create the document object model (DOM), let’s load the file called camera.svg

auto dom = svgdom::load(fsif::native_file("camera.svg"));

Then we just render the SVG into a memory buffer

auto result = svgren::render(*dom);
// returned 'result.pixels' is a std::vector<uint32_t> holding array of RGBA values.

If SVG document specifies any coordiantes or lengthes in physical units, like milimeters or centimeters or inches, we have to supply the dots per inch (DPI) value of our physical display to the svgren::render() function. This is done using the svgren::parameters structure

svgren::parameters p;
p.dpi = 240; // pixel density of target physical display is 240 dpi
p.dims_request.x() = 0; // 0 means use width from SVG document
p.dims_request.y() = 0; // 0 means use height from SVG document
auto result = svgren::render(*dom, p);

After that one can use the rendered image data to display it on any physical display or whatever.